• Nuclear Engineering and Technology
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• v.56 no.8
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• pp.3435-3449
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• 2024

Considering that system analysis codes are used for the evaluation of the performance of Passive Safety Systems (PSSs), it is important to investigate the capability of the system analysis code to reliably predict the heat transfer and natural circulation flow, which are the main phenomena governing the performance of a PSS. Since MARS-KS has been widely validated for heat transfer models, this study focuses on evaluating its capability to predict the single and two-phase pressure drops and natural circulation flow. The straight pipe simulation results indicate that the pressure drop predictions are reliable within ±5 % error margin for the single-phase flow and the errors of pressure drop up to - 30 % for the two-phase flow. Through single-phase natural circulation flow analysis, it is concluded that the use of the appropriate K-factor modeling based on the flow regimes is important since the natural circulation flow rate in MARS-KS is mainly affected by the form loss factor modeling. With two-phase natural circulation flow analysis, this study emphasizes the behavior of the system could change significantly depending on the two-phase wall friction and pressure loss modeling. With the analysis results, modeling considerations for the PSS performance evaluation with the system analysis codes are proposed.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.04b
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• pp.559-565
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• 1998

Flexural tests on 2.4m long reinforced concrete beams with epoxy-bonded GFRP plates are reported in these tests. The selected experimental variables are strengthening plate length, plate thickness, plate width and the method of anchoring the plate ends. The effects of these variables in overall behavior are discussed. The results generally indicate that the flexural strength of strengthened beams is increased. The ductile behavior of tested beams in inversely proportional to the plate thickness, plate width. The use of an U-jacket plate provided a proper anchorage system and improved the ductility of beams.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1993.04a
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• pp.73-82
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• 1993

Over the last decades, interest in the application of decision support systems(DSS) in organizations has increased rapidly. Desipte the growing number of investigations examining decision support system, relatively few empirical studies have evaluated the effects of DSS on problem-solving processes. This study examined, using a computer simulation technique, the effect of recursion in problem-solving processes about the problem-solving time. Results indicate that the recursion at the early stage of problem-solving processes scarcely influenced the problem-solving time, which is contrasted with the case of the recursion at the final stage.

• Journal of the Korean Society of Marine Environment & Safety
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• v.5 no.2
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• pp.87-97
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• 1999

This study is concerned with developing a hybrid heuristic algorithm for solving the redundancy optimization problem which is very important in system safety, This study develops a HH(Hybrid Heuristic) method combined with two strategies to alleviate the risks of being trapped at a local optimum. One of them is to construct the populations of the initial solutions randomly. The other is the additional search with SA(Simulated Annealing) method in final step. Computational results indicate that HH performs consistently better than the KY method proposed in Kim[8]. Therefore, the proposed HH is believed to an attractive to other heuristic methods.

• Journal of Industrial Technology
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• v.31 no.B
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• pp.59-65
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• 2011

In this study, LCD Cell process has been analyzed through ARENA simulation. The major concern is to find the condition maximizing production rate (or quantity per hour). For the analysis, we have selected 4 factors and performed simulation experiments through $L_8(2^7)$ orthogonal arrays. Our results indicate that the production may be maximized with well selected conditions proposed in this study. The results obtained from this study may provide a good base for practical applications.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.493-497
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• 1991

A problem of analysis and design of asymptotically reliable serial production systems, closed with respect to the number of carriers that transport parts between operations, is addressed. A case study of a paint shop operation at a modern automobile assembly plant is described. The results obtained indicate that optimization of the system with respect to the number of carriers available and the capacity of the feedback buffer leads to a substantial improvement in the production rate.

• Proceedings of the IEEK Conference
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• 2000.11b
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• pp.75-78
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• 2000

This paper presents a new algorithm for allocating the data path to achieve the minimum power consumption under the constraints of minimum hardware resources. In order to minimize the power consumption, the proposed algorithm tries to minimize the input transitions of functional units, unnecessary computations, and size of interconnects in a greedy manner during a]location. Experimental results using benchmarks indicate the proposed algorithm achieves 17.5% power reduction on average, when compared with the genesis-lp［1］high-level synthesis system.

• Journal of Korean Society for Quality Management
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• v.30 no.1
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• pp.118-132
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• 2002

This paper presents a process incapability index to provide manager with various information of process and to reduce cost. The introduced process incapability indices indicate information about mean and variance of manufacturing process and variance of inspection process to evaluate process capability using ratio of variance and difference between target and mean to specification. This model can be used by the scale of six sigma management.

• Journal of Korean Society for Quality Management
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• v.8 no.2
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• pp.23-28
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• 1980

Life of a system involves hazards from various sources which, it is believed, can be assessed by means of quite simple expressions. By a suitable combination of these expressions to provide for the relevance of each of the hazards, it is held that a realistic appraisal of the sensitivity of each type failure can be adequately monitored. This paper accordingly presents the mathematical concepts in relation to each of the hazards and then proceeds to indicate the general relationship which these have to some experiences in life monitoring.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.17 no.31
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• pp.141-154
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• 1994

This thesis looks out for the korean trade present condition of the korean machinery industry through time series data, analyze the problem about machinery industry by deepening the trade imbalance between JAPANESE and KOEA (The trabe balance of payment about machinery between JAPANESE and KOREA, US＄7,750,000,000 in 1992, us＄8,450,000 in 1993,US＄9,500,000,000 in 1994 forecast), have shown a reform measure of the balance of payment with indicate the importance of rearing the machinery industry.